Neutron-rich nuclei produced at zero degrees in damped collisions induced by a beam of 18O on a 238U target

Cross sections and corresponding momentum distributions have been measured for the first time at zero degrees for the exotic nuclei obtained from a beam of 18O at 8.5 MeV/A impinging on a 1 mg/cm2 238U target. Sizable cross sections were found for the production of exotic species arising from the neutron transfer and proton removal from the projectile. Comparisons of experimental results with calculations based on deep-inelastic reaction models, taking into account the particle evaporation process, indicate that zero degree is a scattering angle at which the differential reaction cross section for production of exotic nuclei is at its maximum. This result is important in view of the new generation of zero degrees spectrometers under construction, such as the S3 separator at GANIL, for example

Elastic scattering of the lightest radioactive isobar nuclei

International audienc

Applications of (3)He neutron detectors

Neutron detectors with (3)He-filled proportional counters are described. The use of these detectors in measuring the probability of neutron emission (in particular, multiparticle neutron emission) after the beta decay of neutron-rich nuclei and in studying rare events of spontaneous fission of superheavy nuclei is considered

Fission and emission of intermediate mass fragments in asymmetric heavy-ion collisions investigated at the FOBOS 4#pi# - array

The decay of hot heavy nuclei has been studied at the 4#pi#-array FOBOS using the reactions "7Li (43 AMeV)+"2"3"2Th and "1"4N (34 and 52.5 AMeV)+"1"9"7Au. After incomplete fusion, the intermediate system can be excited up to energies of 200-500 MeV. Fission accompanied by the emission of intermediate mass fragments as well as light charged particles ahs been studied. At higher excitation energies, very asymmetric mass splits hav ebeen observed thus pointing out that dynamical effects dominate the decay process. (orig.)13 refs.SIGLEAvailable from TIB Hannover: RR 1847(105) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Study of breakup reactions for Be-11 on Si

This paper presents group discussions taking place within multidisciplinary topical network 33 of the CNRS Information and Communication Science and Technology (STIC) Department. It attempts to clarify the concept of document in its transtion to electronic form, based on research which tends to privilege form (as a material or immaterial object), sign (as meaningful object) or medium (as communication vector). Each of these terms reflects the radical transformations that are taking place. Their superposition stresses the importance of multidisciplinarity for a lucid and complete analysis of the concept and how it is changing

New mass measurements of neutron-rich nuclei near N = 20

International audienceThe masses of 39 neutron-rich nuclei in the mass range 17–37 have been measured using a direct time-of-flight technique following the fragmentation of a 48Ca beam at 55 MeV/nucleon. The masses of 29,30Ne, 34,35Mg and 36,37Al are reported for the first time. The very neutron-rich nuclei, 31–33Na, are found to be 2–4 MeV less bound than previously believed. A comparison is made with recently available large scale shell model calculations encompassing the deformed A∼32 nuclei. Conclusions are drawn regarding the extent of the region of deformation, which is found to include 30Ne

Shape coexistence and the \mth{N=20} shell closure far from stability by inelastic scattering

Following mass measurements in the region $N=20$ and $N=28$, we have studied inelastic nuclear scattering for the nuclei $^{34}$Si, $^{33}$Al and $^{32}$Mg. No evidence for a low-lying shape isomeric 0$^+$ state was found in $^{34}$Si, and an upper limit for the population cross-section could be established, rendering its existence very unlikely. A new transition was found in $^{33}$Al, that is a good candidate for a 2p-2h state and therefore a determination of the 2p-2h gap at $N=20$. Inelastic nuclear scattering strongly excites 3$^-$ states, as seen in $^{34}$Si. A strong transition was found in $^{32}$Mg that should correspond to the first 3$^-$ in this nucleus, lying very low as compared to theory and systematics in this region